The redemption of Israel is compared to four things: to harvest, to vine-cutting, to spices and to a woman bearing a child. To a harvest: if a field is reaped before it's time, even its straw is no good, but if in its proper time,
all its yield is good.

To vine-cutting: when the vineyard is gathered before its time, even the vinegar made from it is no good, but if gathered in its time, it's vinegar is also good.

To spices: if spices are gathered, when they are moist and soft, they do not give off scent, but if gathered when they are dry, they give off scent.

To a woman bearing a child: if the woman gives birth before the right time, the child may not live, but if at the right time, the child will live.

Rabbi Acha said in the name of Rabbi Yehoshua ben Levi: “I the Lord will hasten it in its time (Isaiah 60:22).” If you are not worthy, redemption will occur at its due time; if you are worthy, I will hasten it. (Epilogue to Midrash of Song of Songs)